Window assemblies having fire glass panes of the embedded wire type have heretofore been employed for various uses including applications in penal and other institutions. Such window assemblies are generally satisfactory, but certain problems are encountered in use. For example, inmates may hit their heads against the wire glass causing the glass to shatter and resulting in injury to the inmates and rendering the glass useless or substantially useless as a fire stop. Other forms of impact loading may of course also occur as in the impingement of hard objects on the panes including fire arm projectiles.